Peripheral wheel for machining the edges of slabs

ABSTRACT

A peripheral wheel for machining the edges of slabs, comprising an internal wheel body, to be fixed to a spindle or other machine, and an external abrasive ring, which is adapted to work in contact with an edge of a slab, the abrasive ring being composed of at least two portions that have respective abrasive surfaces having different abrasive capacities—one polishing with respect to the other; the portions of abrasive ring being juxtaposed with respect to each other with surfaces that extend at least partly transversely with respect to the axis of rotation of the peripheral wheel.

The present invention relates to a peripheral wheel for machining the edges of slabs.

The field of the invention is the machining, and particularly the shaping, of the edge of glass materials, ceramic materials and stone-like materials, both natural and synthetic.

Generally, shaping is provided by means of particular tools, i.e., peripheral wheels with diamonds or abrasive, with which the steps of cutting and roughing, lapping, polishing and glazing are performed.

These peripheral wheels are mounted on contouring machines, which can be manual, automatic and of the numeric-control type.

Currently, diamond or abrasive peripheral wheels, one of which is designated by A and exemplified in FIG. 1, are composed of:

-   -   a wheel body B, on which the chamber for the flow of the         internal water for refrigeration of the tool, if any, and the         couplings for connection to the spindle/machine (usually one or         more holes) are provided; the dimensions and shapes of the wheel         body depend on the type of contouring machine used in shaping;         the material used to provide the wheel body can be metallic         material, plastic material (resinoid/rubber-like), or have the         same composition as the abrasive part of the tool (abrasive         ring, as described hereinafter);     -   an abrasive ring C, i.e., the portion that works in contact with         the edge of the slab and gives it the desired profile and         characteristics; this ring can be constituted by sintered         diamond material or abrasive metallic material for use in the         cutting/roughing step; by sintered diamond material or abrasive         resinoid material for use in the lapping step; by sintered         diamond material or abrasive polishing material for use in the         polishing/glazing step.

This abrasive ring can have a continuous shape, or a shape with sectors, depending on whether one wishes to give the tools a higher finishing capacity (continuous ring) or cutting capacity (ring with sectors).

The abrasive ring is shaped in cross-section according to a profile the shape of which yields the desired profile at the edge E of the slab L to be machined.

The shapes of the profiles can vary widely according to the requirements of the market.

Holes for the passage of water D are also present; most peripheral wheels work wet, with water or water supplemented with a coolant.

Where refrigeration can be external and internal, a chamber for containing the water that arrives from the spindle, on the wheel body A, and holes/channels that reach the containment chamber on the wheel body from the profile of the tool/wheel, are provided in the tool.

In this manner, the surface of the profile in contact with the edge of the slab during machining/passage is cleaner and better refrigerated.

For providing a specific profile, diamond/abrasive peripheral wheels are used on the edge of slabs of materials described above.

Depending on their technical characteristics (removal/cutting and finishing capacity), due to the type of sintered material and the size of the diamond/abrasive element (particle size) used, they are used in sequence on contouring machines until the desired profile/degree of finishing is obtained.

Depending on the type of contouring machine used for machining, which can be manual, automatic or of the numeric-control type, the tools are:

-   -   mounted all together in sequence: in this case the slab is         induced to slide along a system of conveyor belts and the edge         is machined in sequence by the various tools;     -   one at a time on a same spindle/motor: in this case the slab         remains stationary and the tool is induced to pass along the         edge by means of a spindle/motor that turns around the slab and         is moved manually or automatically.

In both cases, the machining of the edge to provide the profile is composed of the following steps:

-   -   cutting/roughing, with the use of tools with high removal         capacity, with a metallic bonding agent and diamonds, or other         abrasive elements, of large particle size;     -   lapping, with the use of tools with cutting/finishing capacity         with a metallic bonding agent, or resinoid substance and         diamonds, or other abrasive elements, of medium/small particle         size;     -   polishing or glazing, with the use of tools with high finishing         capacity with a resinoid bonding agent and diamonds, or other         abrasive elements, of small particle size.

Because of its nature, each peripheral wheel used in the various steps leaves machining lines on the edge of the slab.

In the machining systems described above, these lines are even more evident because the rotation of the wheel A, designated by the arrow G, and the direction, designated by the arrow F, of the machining of the slab L have the same advancement direction and the wheel operates on a plane P which is parallel to the plane of the slab to be machined, as shown in FIG. 2.

In order to increase the degree of finishing that one wishes to obtain, i.e., to reduce what are called machining lines, one or more passes are performed on the edge of the slab to be shaped, in the various machining steps.

This can occur:

-   -   by machining the edge with tools having progressively smaller         particle sizes of diamond/abrasive, this being the most used         system, and the higher the number of passes, the higher the         number of tools used in order to obtain a better finishing of         the edge/profile;     -   by machining with oscillation, i.e., with an auxiliary movement         of the wheel in a direction that is transverse to the         advancement direction of said wheel; in order to machine with         oscillation, the wheel is mounted on a spindle that is adapted         to vary its height with respect to the working plane of the slab         during shaping (oscillation).

By making one or more tools machine with oscillation in one or more steps/passes, the machining lines are reduced more drastically and rapidly, because the tool that machines with oscillation removes the lines created by the tool used in the previous pass.

The provision of a specific profile with the systems described above, in order to have an excellent degree of finishing, i.e., with a drastic reduction and preferably elimination of machining lines, has some drawbacks.

A first drawback is linked to the use of wheels with ever smaller particle sizes.

This use of a plurality of wheels with different particle sizes in fact entails working times that comprise both the pass times of the various wheels and the times for replacing one wheel with another.

Moreover, the plurality of wheels used entails considerable investments in terms of equipment.

In the case of wheels that machine with oscillation, the further drawback that this system cannot be used for shaped profiles, as exemplified in FIGS. 3 to 5, is evident; in this case, in fact, it is necessary to resort to a planar peripheral wheel A1 in order to machine with oscillation the straight portion E1 of the profile (FIG. 3) and an additional peripheral wheel A2 in order to machine the bevels E2 (FIG. 4).

This means an additional pass and an additional tool, which entail higher costs.

It is possible to use a single tool A3, as in FIG. 5, that machines at the same time the straight portion and the bevels of the profile, but with which it is not possible in any case to machine with oscillation.

The aim of the present invention is to provide a peripheral wheel for machining the edges of slabs that is capable of obviating the cited drawbacks of the background art.

In particular, within the scope of this aim, an important object of the invention is to provide a peripheral wheel capable of improving the machining of the surface of the edge of a slab, resorting to fewer tools and requiring less time.

Another object of the invention is to provide a peripheral wheel that can be mounted easily on spindles and working machines of the known type.

A further object of the invention is to provide a peripheral wheel whose performance and lifetime are not below those of wheels of the known type.

Another object of the invention is to provide a wheel for machining slabs of glass material, ceramic material, stone-like material, and also wood material, metallic material and plastic material, as well as other similar and equivalent materials.

Another object of the invention is to propose a peripheral wheel for machining edges of slabs that can be provided with known systems and technologies.

This aim and these and other objects that will become more apparent hereinafter are achieved by a peripheral wheel for machining the edges of slabs, of the type comprising an internal wheel body, to be fixed to a spindle or other machine, and an external abrasive ring, which is adapted to work in contact with an edge of a slab, said peripheral wheel being characterized in that said abrasive ring is composed of at least two portions that have abrasive surfaces having different abrasive capacities—one polishing with respect to the other, said portions of the abrasive ring being juxtaposed with respect to each other along a surface that extends at least partly transversely with respect to the axis of rotation of said peripheral wheel.

Further characteristics and advantages of the invention will become more apparent from the description of four preferred but not exclusive embodiments of the peripheral wheel according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

FIG. 1 is a view of a peripheral wheel of a known type;

FIG. 2 is an exemplifying perspective view of how a wheel of a known type machines;

FIGS. 3 to 5 are views of other applications of peripheral wheels of a known type;

FIG. 6 is a perspective view of a peripheral wheel according to the invention in a first embodiment;

FIG. 7 is a schematic exploded view of the wheel of FIG. 6;

FIG. 8 is a perspective view of a peripheral wheel according to the invention in a second embodiment;

FIG. 9 is a schematic exploded view of the wheel in FIG. 8;

FIG. 10 is an exemplifying view of the operation of the wheel according to the invention;

FIG. 11 is a perspective view of a peripheral wheel according to the invention in a third embodiment;

FIG. 12 is a perspective view of a peripheral wheel according to the invention in a fourth embodiment.

With reference to the cited figures, a peripheral wheel for machining the edges of slabs, according to the invention, is generally designated by the reference numeral 10.

Said wheel 10, in a first embodiment as shown in FIGS. 1 and 2, comprises an internal wheel body 11, to be fixed to a spindle or other machine, not shown for the sake of simplicity and to be understood as being of a known type, and an external abrasive ring 12, which is adapted to work in contact with an edge of a slab.

The particularity of the peripheral wheel 10 according to the invention resides in that the abrasive ring 12 is composed of two portions 13 and 14, respectively, that have respective abrasive surfaces 15 and 16 with different abrasive capacities—one polishing with respect to the other, and particularly having a different degree of particle size with respect to each other.

The generic abrasive-polishing capacity is distinguished from the particle size because the quality of the finish is defined by the abrasive capacity of the diamond powder together with the abrasive capacity of the bonding agent with which this powder is mixed, and the bonding agent contributes to the finish.

The portions of the abrasive ring 13 and 14 are juxtaposed with respect to each other with respective contact surfaces 17 and 18 that extend transversely with respect to the axis of rotation X of said peripheral wheel 10.

The wheel body 11 is constituted by a tubular element, for example made of resin or aluminum, or of a mixture of resin with aluminum powder, in which refrigeration holes 20 for the passage of water are provided.

The contact surfaces 17 and 18, in this constructive example, are parallel to a plane P1 which is inclined by an angle W with respect to a plane P2 which is at right angles to the axis of rotation X.

In particular, this inclined plane P1 passes both through a point of the upper perimetric rim 23 of the first portion 13 and through a point of the lower perimetric rim 24 of the second portion 14.

The two portions 13 and 14 of the ring 12 have through holes 21 and 22 that correspond to the refrigeration holes 20 of the wheel body 11.

Constructive variations in which the wheel body and the rim 12 do not have any refrigeration holes are to be considered as being comprised within the invention.

These portions 13 and 14 are substantially annular, with the abrasive surfaces 15 and 16 shaped, by way of example, for the machining of an edge of a slab with bevels on both rims.

A first portion 13 has, for example, an abrasive surface 15 with a high removal capacity, with a metallic bonding agent and diamonds, or other abrasive elements, having a large particle size; the second portion 14, on the other hand, has an abrasive surface 16 with a cutting/finishing capacity with a metallic bonding agent or resinoid substance and diamonds, or other abrasive elements, having a medium/small particle size.

The peculiar shape of the two portions 13 and 14 determines an alternation of the abrasive surfaces 15 and 16 in contact with the edge of the slab that has a substantial sinusoidal pattern, as shown in FIG. 10.

In this manner, the wheel 10 according to the invention simulates an abrasive oscillatory motion for each one of the two different abrasive surfaces that by means of the rotation of the wheel 10 alternate in the machining of the edge of the slab, without the spindle, on which the tool is mounted, translating laterally with respect to the advancement direction of the wheel along the edge of the slab.

FIGS. 8 and 9 show a second embodiment of a peripheral wheel according to the invention, designated therein by the reference numeral 110.

Said peripheral wheel 110 has an abrasive ring 112 which is divided into three portions, respectively 113, 114 and 130, which have respective abrasive surfaces 115, 116 and 131 having different degrees of particle size with respect to each other, or the two upper and lower portions 113 and 114 have an equal particle size and the central portion 130 has a different particle size.

The abrasive ring portions 113, 114 and 130 are mutually juxtaposed with respective contact surfaces 117, 118, 132 and 133 that extend transversely with respect to a plane that is at right angles to the axis of rotation of said peripheral wheel 110.

The contact surfaces 117, 118, 132 and 133, in this constructive example as well, are parallel to a plane that is inclined with respect to a plane that is perpendicular to the axis of rotation, in the same manner as described above for the first embodiment of the peripheral wheel 10.

In particular, the two inclined planes P3 and P4 on which the contact surfaces lie, respectively 117 and 132 on the first plane P3 and 118 and 133 on the second plane P4, are parallel. The first plane P3 passes through a point of the upper perimetric rim 123 of the first portion 113, whereas the second plane P4 passes through a point of the lower perimetric rim 124 of the second portion 114.

The three portions 113, 114 and 130 of the rim 112 also have through holes 121 and 122 that correspond to the refrigeration holes 120 of the wheel body 111.

These portions 113, 114 and 130 are substantially annular, with the abrasive surfaces 115, 116 and 134 shaped, by way of example, in order to machine a slab edge with bevels on both rims.

A first portion 113 has, for example, an abrasive surface 115 with a high removal capacity, with a metallic bonding agent and diamonds, or other abrasive elements, having a large particle size; the second portion 114 has instead an abrasive surface 116 with a high finishing capacity with resinoid bonding agent and diamonds, or other abrasive elements, having a small particle size; the third central portion 130 has an abrasive surface 134 of a type that is intermediate between the first two, i.e., with a cutting/finishing capacity with a metallic bonding agent or resinoid substance and diamonds, or other abrasive elements, having a medium/small particle size.

FIG. 11 exemplifies a third embodiment of a peripheral wheel according to the invention, designated therein by the reference numeral 210.

Said wheel 210 has three annular portions 213, 214 and 230 which are juxtaposed along mutually parallel inclined planes, said annular portions defining an overall abrasive surface that has a cylindrical shape and is therefore adapted for planar edges.

FIG. 12 exemplifies a fourth embodiment of a peripheral wheel according to the invention, designated herein by the reference numeral 310.

Said wheel 310 has three annular portions 313, 314 and 330 which are juxtaposed along mutually parallel inclined planes, particularly with the first annular portion 313 and the second annular portion 314 having sectors 313 a, 313 b, 314 and 314 b which are straight or inclined and adapted to ensure higher cutting and removal capacity in general.

In one embodiment of the wheel according to the invention that is not shown for the sake of simplicity but is to be intended as providable, the wheel body is monolithic with at least one of the portions of the ring.

In general, a peripheral wheel according to the invention, shown herein as provided with an abrasive ring composed of two or three portions, can be provided also with an abrasive ring with a plurality of portions, depending on the requirements of the user.

The various annular portions are, for example, provided separately and then assembled on the wheel body.

As an alternative, the annular portions are provided directly on the wheel body in sequence by means of working methods with successive steps.

The particle sizes of the annular portions that compose the abrasive ring can differ more or less depending on the planned uses of the wheel.

The types of bonding agent with which the sintered elements of the annular portion are provided can be for example:

-   -   metallic bonding agents/sintered elements for a cutting/roughing         wheel;     -   resinoid bonding agents/sintered elements for a         lapping/polishing wheel;     -   polishing bonding agents/sintered elements for a         polishing/glazing wheel.

It is understood that the number, shapes and dimensions of the annular portions of which the abrasive ring is composed may have various forms depending on the characteristics to be given to the wheel.

A correct and appropriate blending of the cited aspects of the annular portions that compose the abrasive ring, particle size, type of bonding, dimensions and shape, which are adapted to determine alternating passes of abrasive surfaces having different characteristics with simultaneous simulation of an oscillatory movement, provides the wheel according to the invention with a better cutting/finishing capacity than a normal commercially available tool.

An intermediate annular portion can be also constituted by an empty space, or with an inert/lubricant material, or with a material that is harder than the other annular portions; in these cases one obtains a better refrigeration of the tool and a smaller deformation of its profile.

A peripheral wheel according to the invention is particularly adapted for the shaping of edges of slabs made of glass material, ceramic material, stone-like material and the like.

In practice it has been found that the invention fully achieves the intended aim and objects.

In particular, the invention provides a peripheral wheel capable of reducing, if not eliminating, more quickly the working lines on the edge of the slab to be shaped, and therefore capable of improving the quality of the edge in shorter times than can be provided by the background art with the use of a plurality of different wheels in series or with the use of spindles that can translate vertically so as to provide an oscillation machining.

Moreover, the invention provides a peripheral wheel with an abrasive ring that can be shaped for the machining of profiles that are not only planar but also complex.

Moreover, the invention provides a peripheral wheel that can be used on contouring machines of a known type, whether they are manual, automatic or with numeric control.

Furthermore, the invention provides a peripheral wheel capable of a better degree of cutting/finishing for each pass than a normal tool.

Moreover, a peripheral wheel according to the invention undergoes, thanks to the interposition, between two upper and lower annular portions, of an intermediate portion which has a greater hardness than the others and less deformation and which is therefore capable of better respecting the tolerances of the machining profile of the abrasive ring.

Moreover, from the point of view of economic impact, a peripheral wheel according to the invention allows performing a smaller number of working passes on the edge of the slab, obtaining at the same time a better quality of the edge, using a smaller number of tools than the working methods currently in use.

Furthermore, the invention provides a peripheral wheel that has a longer life and therefore is capable of machining for a longer period of time while providing profiles whose dimensions remain completely within the tolerances.

Moreover, the invention provides a wheel that can be provided specifically for machining slabs made of glass material, ceramic material, stone-like material, and also wood material, metallic material and plastic material, as well as other similar and equivalent materials.

Last but not least, the invention provides a peripheral wheel that can be manufactured with known systems and technologies.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the accompanying claims; all the details may furthermore be replaced with other technically equivalent elements.

In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

The disclosures in Italian Patent Application no. PD2011A000305, whose priority is claimed in this application, are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs. 

1-10. (canceled)
 11. A peripheral wheel for machining the edges of slabs, of the type comprising an internal wheel body, to be fixed to a spindle or other machine, and an external abrasive ring, which is adapted to work in contact with an edge of a slab, wherein said abrasive ring is composed of at least two portions that have respective abrasive surfaces having different abrasive capacities—one polishing with respect to the other, said portions of the abrasive ring being juxtaposed with respect to each other with contact surfaces that extend at least partly transversely with respect to an axis of rotation of said peripheral wheel.
 12. The peripheral wheel according to claim 11, wherein said wheel body is constituted by a tubular element in which refrigeration holes for the passage of water are provided.
 13. The peripheral wheel according to claim 11, wherein said contact surfaces are parallel to a plane which is inclined by an angle with respect to a plane which is perpendicular to the axis of rotation.
 14. The peripheral wheel according to claim 13, wherein said inclined plane passes both through a point of an upper perimetric rim of a first portion of said two portions and through a point of a lower perimetric rim of a second portion of said two portions.
 15. The peripheral wheel according to claim 11, wherein said portions are substantially annular.
 16. The peripheral wheel according to claim 11, wherein a first portion of said two portions has an abrasive surface with a high removal capacity, with a metallic bonding agent and diamonds, or other abrasive elements, having a large particle size, a second portion of said two portions having an abrasive surface with a cutting/finishing capacity with a metallic bonding agent or resinoid substance and diamonds, or other abrasive elements, having a medium/small particle size.
 17. The peripheral wheel according to claim 11, further comprising an abrasive ring which is divided into three portions which have respective abrasive surfaces with mutually different degrees of particle size, or where two upper and lower portions have an equal particle size and a central portion has a different particle size.
 18. The peripheral wheel according to claim 17, wherein said abrasive ring portions are mutually juxtaposed with respective contact surfaces that extend transversely with respect to a plane which is perpendicular to the axis of rotation of said peripheral wheel.
 19. The peripheral wheel according to claim 11, comprising three annular portions which are juxtaposed along mutually parallel inclined planes, said annular portions defining an overall abrasive surface that has a cylindrical shape.
 20. The peripheral wheel according to claim 11, comprising three annular portions which are juxtaposed along mutually parallel inclined planes, with a first annular portion and a second annular portion having sectors which are straight or inclined and adapted to ensure a higher cutting and removal capacity in general. 